Rooftop Exhaust Fan Having a Mechanism for Locking the Fan in an Open Position

ABSTRACT

The present invention relates to a rooftop exhaust fan that is pivotally mounted to a curb or other support structure and which, in response to pivoting the exhaust fan from a closed position to an inclined open position, the exhaust fan is automatically locked in the inclined open position.

FIELD OF THE INVENTION

The present invention relates to rooftop ventilation systems.

BACKGROUND OF THE INVENTION

Rooftop ventilation systems are employed in various applications. Theyare used in general ventilation applications to exhaust air from abuilding. They are also employed on rooftop commercial kitchens toexhaust smoky and grease-laden air that is exhausted through a kitchenhood. These ventilation systems must be cleaned, maintained and eveninspected by regulatory officials. This means that they must be openedin order that access can be gained to components of the exhaust fan andto an underlying duct. Opening some rooftop exhaust systems andmaintaining them opened is not always easy. Once opened, the taskbecomes maintaining them opened without inadvertently closing.

SUMMARY OF THE INVENTION

The present invention relates to a rooftop exhaust fan that is pivotallymounted to a curb or other support structure and which in response topivoting the exhaust fan from a closed position to an inclined openposition, the exhaust fan is automatically locked in the inclined openposition.

In one particular embodiment, a spring loaded locking pin is disposedadjacent the exhaust fan. As the exhaust fan is pivoted from the closedposition towards the open position, the locking pin engages and rides ona cam surface until a locking pin opening aligns with the locking pin,after which the spring loaded locking pin is projected into the lockingpin opening, thereby stationing and locking the exhaust fan in aninclined open position.

In another embodiment, a pivot art is attached to the exhaust fan and inthe course of pivoting from the closed position to the open position,the exhaust fan rotates about an axis. The cam surface and locking pinopening are formed on the pivot arm. As the pivot arm pivots with theexhaust fan, the cam surface is brought in contact with the locking pinand moves the locking pin against the biasing force of the spring, afterwhich the locking pin opening comes into alignment with the locking pinand the locking pin springs back and is projected into the locking pinopening.

Other objects and advantages of the present invention will becomeapparent and obvious from a study of the following description and theaccompanying drawings which are merely illustrative of such invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of the exhaust fan of the presentinvention shown mounted on a roof and disposed in the closed position.

FIG. 2 is a side elevational view of the exhaust fan shown in theinclined open position.

FIG. 3 is a fragmentary side elevational view showing the lockingassembly incorporated into the exhaust fan for stationing and lockingthe exhaust fan in the open position.

FIG. 4 is a view similar to FIG. 3 except that the locking assembly isdisposed in the locked position.

FIG. 5 is a fragmentary perspective view of the locking assemblyincorporated into the exhaust fan.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

With further reference to the drawings, an exhaust fan or exhaust fanassembly is shown therein and indicated generally by the numeral 10. Inthe embodiment illustrated, the exhaust fan is what is generallyreferred to as an upblast type. It is understood and appreciated bythose skilled in the art that the present invention can easily beemployed with a downblast-type exhaust fan. As noted above, the exhaustfan 10 can be used for general ventilation or can be used in conjunctionwith a commercial kitchen to exhaust smoky and grease-laden air thatemanates from a cooking surface generally disposed underneath a hood.

Viewing the exhaust fan in more detail, it is seen that the sameincludes a base 12. Extending upwardly from the base 12 is a baffle 13.Baffle 13 transitions into an apron 14. Apron 14 forms a large bowlhaving a central opening that is aligned with the baffle 13.

Exhaust fan 10 is provided with a means for inducing air to moveupwardly through the exhaust fan where the air is exhausted to theatmosphere. Various fan and motor arrangements can be incorporated intothe exhaust fan 10. In this exemplary embodiment, the exhaust fan 10includes a fan wheel or propeller for generating an upwardly movingsystem of air. In the case of the exhaust fan assembly shown in thedrawings, a fan wheel is provided. It is understood and appreciated tothose skilled in the art that various types of fans can be incorporatedinto the exhaust fan assembly 10. Fan wheel 16 is centrally mounted inthe exhaust fan 10 and is supported by internal structure that is wellappreciated by those skilled in the art. Fan wheel 16 is driven by amotor 18. Typically the motor 18 is aligned with and disposed over orunder the fan wheel or propeller in the case of a direct drive design.Generally when a direct drive is employed, the fan wheel or propeller isessentially mounted to the drive shaft of the motor 18 or to anextension therefrom. In other cases, the fan wheel or propeller can bedriven from a side mounted motor through a belt drive.

In order to protect the motor 18, as well as the fan wheel or propeller,the exhaust fan is provided with a housing 20. Note that the housing 20partially encompasses both the motor 18 and the fan wheel 16. When thefan wheel 16 is driven by the motor 18, this results in a system of airmoving upwardly through the exhaust fan 10. There is provided an annularopening formed generally between the housing 20 and the apron 14. It isthrough this annular opening that the air is exhausted from the exhaustfan.

Typically, the exhaust fan 10 is of the type that is mounted on the roofof a building. See FIGS. 1-2. In particular, there is provided a curb orsupport structure 22 that extends upwardly from the roof. Exhaust fan 10is mounted and supported by the curb or support structure 22. Note asseen in the drawings where the base 12 of the exhaust fan 10 sits on thecurb or support structure 22. Furthermore, it is appreciated that thecurb or support structure 22 is communicatively connected to anunderlying duct or duct network that extends from the curb.

As discussed above, the exhaust fan 10 is pivotally mounted to the curbor support structure 22 such that it can move from a closed position(FIG. 1) to an inclined open position (FIG. 2). In the closed position,the base 12 extends transversely across the top of the curb or supportstructure 22. In the inclined open position, the fan assembly 10 ispivoted such that there is an open area between the curb or supportstructure 22 and the base 12 of the fan assembly. This enables repairand maintenance personnel to gain access to the fan wheel 16, motor 18and the area around the fan wheel and motor, as well as the interior ofthe curb or support structure 22.

In order to secure the exhaust fan 10 in the inclined open position formaintenance, cleaning or inspection, the exhaust fan of the presentinvention is provided with a locking assembly, indicated generally bythe numeral 30, for stationing and locking the exhaust fan in theinclined open position. Viewing the locking assembly 30 in detail, asupport plate 32 is fixed to the curb or other support structure 22. Alocking pin 34 is supported on the support plate 32. In particular, thelocking pin 34 is held by a locking pin holder 36 that projectsoutwardly from the support plate 32. Locking pin holder includes anupper plate 36A and a pair of spaced apart flanges 36B and 36C. See FIG.5. Openings are provided in the flanges 36B and 36C. As shown in thedrawings, locking pin 34 projects through the openings in the flanges36B and 36C. A coil spring 38 is disposed around the portion of thelocking pin disposed between the two flanges 36B and 36C. In thisembodiment, the right end of the spring 38, as viewed in FIG. 5, isfixed to the locking pin 34 while the other end of the coil springengages the left most flange 36B.

A tab 40 extends outwardly from one edge of the support plate 32. SeeFIGS. 3-5. As described below, the function of the tab 40 is to limitthe rotation of the exhaust fan 10 as the fan assembly rotates from theclosed position to the inclined open position.

A pivot arm 50 is connected to the exhaust fan 10. In the case of thisembodiment, as shown in the drawings, the pivot arm 50 is fixed to thebase 12 of the fan assembly 10. Pivot arm 50 in this embodiment assumesa generally L-shape. Another portion of the pivot arm 50 is pivotallyconnected to the plate 32 about pivot pin 60 or another adjacent fixedstructure. It is the pivot arm 50 that enables the exhaust fan to bepivoted back and forth between the closed and open positions.

Pivot arm 50 includes a flange 50A that projects outwardly from thepivot arm. Flange 50A about a terminal end thereof includes a camsurface or ramp 52 disposed on one terminal end. Furthermore, formed inthe flange 50A is a locking pin opening 54. Note that the cam surface 52and the locking pin opening 54 lie in the same plane as the locking pin34. As seen in the drawings, when exhaust fan 10 assumes the closedposition, the cam surface 52 is angled with respect to that portion ofthe flange 50A that contains the locking pin opening 54. In thisposition, the cam surface 52 lies above the locking pin opening 54.

A brief review of the locking assembly 30 and how it stations and locksthe exhaust fan 10 in the inclined open position follows. To gain accessto the interior of the exhaust fan 10 and to at least a portion of thecurb 22, the exhaust fan is pivoted from the closed position to theinclined open position. As the exhaust fan is rotated clockwise, asviewed in FIGS. 1-2, it follows that the pivot arm 50 secured theretoalso rotates. As the exhaust fan rotates towards the open position, thecam surface 52 moves towards the locking pin 34. Since the cam surface52 is aligned with the locking pin 34 and lies in the same plane of thelocking pin, it follows that at some point the locking pin 34 willengage the cam surface 52. This occurs just prior to the fan assembly 10reaching the inclined open position. Once the locking pin 34 is engagedby the cam surface 52, the locking pin tends to ride the moving camsurface 52 until the locking pin opening 54 aligns with the locking pinopening 54. As the locking pin 34 rides on the moving cam surface 52,the coil spring 38 is compressed. This is because one end of the coilspring, as pointed out above, is fixed to the locking pin. Once thelocking pin opening 54 is rotated to a point where it aligns with thelocking pin 34, the spring 38 biases the locking pin into and throughthe locking pin opening 54. Now the exhaust fan 10 is stationed andlocked in the inclined open position. The locking pin will prevent theinadvertent closing of the exhaust fan 10. Now the exhaust fan 10 can becleaned, maintained, repaired or even inspected if periodic inspectionsare required.

To bring the exhaust fan 10 back to the closed position, the locking pin34 is manually retracted from the locking pin opening 54 and the fanassembly is slowly lowered from the open position to the closed positionwhere the base 12 of the fan assembly 10 seats on the curb or supportstructure 22.

There are many advantages to the automatic locking assembly 30 that isincorporated into the exhaust fan 10. First, the locking assembly 30 issimple in design and operation. Secondly, the locking assembly 30 isdesigned such that it will automatically lock the exhaust fan 10 in theinclined open position simply as a result of the exhaust fan beingsufficiently rotated to engage the locking assembly. Finally, thelocking assembly is strong and robust and designed to securely supportthe weight of the fan assembly when it assumes the inclined openingposition.

The present invention may, of course, be carried out in other specificways than those herein set forth without departing from the scope andthe essential characteristics of the invention. The present embodimentsare therefore to be construed in all aspects as illustrative and notrestrictive and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

What is claimed is:
 1. A rooftop exhaust system for exhausting air froma building, comprising: a fan assembly pivotally connected to a curb orsupport structure and moveable back and forth from a closed position toa tilted open position; the fan assembly including a base, a housing, amotor disposed in the housing, and a fan driven by the motor andconfigured to induce air to move from the building through the fanassembly; a pivot arm fixed to the housing and extending therefrom andconfigured to pivot about an axis; a locking pin opening disposed on thepivot arm; a cam surface disposed on the pivot arm adjacent the lockingpin opening; a plate configured to be secured to the curb or supportstructure; a spring biased locking pin mounted on the plate and alignedwith the cam surface and the locking opening; and the spring biasedlocking pin, cam surface and locking pin opening configured such that asthe fan assembly is pivoted from the closed position toward the openposition, the spring biased locking pin engages the cam surface andrides along the cam surface and thereafter is biased into the lockingopening which stations and locks the fan assembly in the tilted openposition.
 2. The rooftop exhaust system of claim 1 wherein the pivot armincludes a flange that projects outwardly from the pivot arm and whereinthe locking opening is formed in the flange and wherein the flange isconfigured to form the cam surface.
 3. The rooftop exhaust system ofclaim 2 wherein when the fan assembly assumes the open position, aterminal end portion of the flange includes the cam surface and thelocking opening is disposed in the flange below the cam surface.
 4. Therooftop exhaust system of claim 1 wherein the plate includes a lockingtab that projects outwardly from the plate and is configured to engagethe pivot arm and limit the pivotable movement of the pivot arm.
 5. Therooftop exhaust system of claim 1 wherein the spring biased locking pinis supported within a holder and includes a spring fixed at one end tothe locking pin and confined about the other end by the holder.
 6. Therooftop exhaust system of claim 1 wherein the pivot arm comprises anL-shaped pivot arm including a flange and wherein the cam surface andlocking opening are formed in the flange.
 7. The rooftop exhaust systemof claim 1 wherein the pivot arm is connected to the base of the fanassembly and projects therefrom and pivotally connected to the plate. 8.The rooftop exhaust system of claim 7 wherein the pivot arm assumes agenerally L-shape.
 9. The rooftop exhaust system of claim 1 wherein thepivot arm is pivotally mounted to the plate.
 10. A rooftop exhaustsystem for exhausting air from a building, comprising: a fan assemblypivotally connected to a curb or support structure and moveable from aclosed position to a tilted open position; the fan assembly including ahousing, a motor disposed in the housing, and a fan driven by the motorand configured to induce air from the building through the fan assembly;means for pivoting the fan assembly from the closed position to the openposition; and means for engaging the means for pivoting the fan assemblyand for locking the fan assembly in the open position.
 11. The rooftopexhaust system of claim 10 wherein the means for pivoting the fanassembly from a closed position to an open position comprises a pivotarm pivotally mounted about a transverse axis.
 12. The rooftop exhaustsystem of claim 11 wherein said means for engaging the means forpivoting the fan assembly and for locking the fan assembly in the openposition comprises a spring biased locking pin secured to a plate fixedwith respect to the fan assembly, a flange projecting from the pivotarm, a cam surface formed on the flange and aligned with the locking pinand configured to be engaged by the locking pin as the fan assemblymoves from the closed position toward the open position; and a lockingpin opening formed in the flange adjacent the cam surface.
 13. Therooftop exhaust system of claim 12 further including means disposed onthe plate for engaging and limiting the movement of the pivot arm.
 14. Amethod of opening a rooftop fan assembly and locking the fan assembly inan open position comprising: pivoting the fan assembly from a generallyvertical closed position to an inclined open position; while pivotingthe fan assembly, engaging a spring biased locking pin mounted on astationary structure with a cam surface that moves with the fan assemblyand compressing a spring associated with the locking pin as the lockingpin rides on the cam surface; moving the locking pin on the cam surfacetowards a locking pin opening that also moves with the fan assembly;continuing to pivot the fan assembly until the locking pin openingaligns with the locking pin; and spring biasing the locking pin into thelocking pin opening and securely stationing and locking the fan assemblyin the open position.
 15. The method of claim 14 wherein the stationarystructure comprises a plate mounted to a curb which underlies the fanassembly and wherein the locking pin forms a part of a locking pinassembly that is fixed to the plate.
 16. The method of claim 14 whereinthe cam surface and locking pin opening are disposed on a pivot arm thatis fixed to the fan assembly and pivotally mounted about a transverseaxis.
 17. The method of claim 14 wherein a pivot arm is connected to thefan assembly and moves with the fan assembly from the closed position tothe open position, and wherein the stationary structure includes a tabthat projects into the path of the pivot arm and limits the pivotablemovement of the pivot arm.
 18. The method of claim 14 wherein agenerally L-shaped pivot arm is secured to the fan assembly and moveswith the fan assembly as the fan assembly moves from the closed positionto the open position, and wherein a flange projects from the pivot armand wherein both the cam surface and locking pin opening are disposed onthe flange.